package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.ILock;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;


    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result seckillVoucher(Long voucherId) {

        //1.根据id查询优惠卷
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        //2.判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("活动还未开始！");
        }

        //3.判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("活动已经结束！");
        }

        //4.判断库存是否充足
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足！");
        }
        Long userId = UserHolder.getUser().getId();
        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);

        boolean success = lock.tryLock(1000L);
        if (!success) {
            return Result.fail("已获得优惠券，不能重复领取！");
        }

        try {
            //使用代理类，因为@Transactional注解作用在代理类上，直接使用this会失效
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createOrder(voucherId);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        }finally {
            lock.unlock();
        }


    }


    @Transactional
    public Result createOrder(Long voucherId) {

        Long userId = UserHolder.getUser().getId();

        //5.一人一单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if (count > 0) {
            return Result.fail("用户已购买！");
        }

        //5.扣减库存
        boolean isSuccess = seckillVoucherService.update().setSql("stock = stock - 1").eq("voucher_id", voucherId).gt("stock", 0).update();
        if (!isSuccess) {
            return Result.fail("库存不足！");
        }

        //6.创建订单号
        VoucherOrder order = new VoucherOrder();
        //6.1生成订单id
        long orderId = redisIdWorker.nextId("seckill");
        order.setId(orderId);
        //6.2用户id
        order.setUserId(userId);
        //6.3代金券id
        order.setVoucherId(voucherId);
        save(order);

        //7.返回订单id

        return Result.ok(orderId);
    }
}
